Abstract：Using CryoSat-2 satellite altimetry data, the sea ice thickness in the Beaufort Sea is retrieved. The accuracy of the results is evaluated using the ULS data in October 2010 to 2013 and IceBridge data in 2011. The results show that the maximum and standard deviations of the difference between the sea ice draught depth and ULS draught depth are 14 cm and 4 cm, respectively. The average and standard deviations of the difference between the sea ice thickness and IceBridge sea ice thickness are 2.7 cm and 65.7 cm, respectively, which are better than Laxon’s (2013) research results. The results are optimized by 2.1 cm and 6.6 cm, respectively. On this basis, the variation of sea ice thickness in summer and winter of the Beaufort Sea from 2011 to 2017 is studied. The sea ice thickness in summer and winter has similar distribution characteristics, and the coverage in March of winter is wider and thicker. The interannual variation of sea ice thickness in March of winter of 2011 to 2017 is further analyzed. The results show that the sea ice thickness in 2011 to 2017 shows an overall downward trend, with the smallest in 2012 and the largest in 2014.